<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Parent</title>
  <style>
    h1 {
      font-size: 22px;
    }
  </style>
</head>
<body>

  <h1>Hello, world!</h1>
  <hr>
  <p>以下为iframe页面：</p>
  <iframe src="iframe.html" style="border: none;">
    
  </iframe>
  
</body>
</html>